I have two stalled downloads. The first is at 2.71 of 2.78G (97%). The second is at 3.20 of 3.21M (99%). How to I get them to finish?

spend alot of time looking for alternative trackers. if hashes match you get extra seed without needing to do anything more. sometimes even if torrents hashes do not match, you can copy the file, do a force check and voila, you have most of the torrents progress completed. also check if you have dht enabled

And how does one look for alternative trackers? I haven't a clue how "trackers" work.